The technology used to create and resurface ice on, for example indoor skating rinks, has been relatively unchanged for many years. Skating rink surfaces are typically formed on concrete or sand floors, in which are embedded pipes carrying a chilled brine solution. The brine temperature may be as low as 10° which is well below the 32° F. freezing temperature of water. The chilled hoar is then flooded with water, which freezes onto the chilled floor to farm an ice-surface. Typically, an indoor skating rink will have a layer of ice of about 1½ inches thick in total. The ice is built up to this thickness by repeatedly flooding the surface with layers of water. The layers freeze one onto the next to form an integral ice layer.
The ice may also be painted at one or more of the intermediate layers. For example, to provide good visual contrasts the entire ice surface may be painted white. To prevent the white paint from being marred by skaters, more ice is layered over the white paint, thereby protecting it. Then, additional graphics can be painted on the ice at higher levels. For example, for hockey, the red and blue lines, goal creases, and the like can be painted on, which will then contrast well with the white layer beneath. Further, more recently corporate logos have also now been painted on.
Typically, in the past, the initial ice surface was made by dragging a large hose onto the chilled floor and gradually manually flooding it with hot water. Hot water is preferred because it freezes to a more dense and harder ice surface which improves durability and playability. However, hot water flooding is more labour intensive. Several labourers are required to keep the hose in constant motion, to prevent it from melting through the already formed ice and forming ridges or damaging for example, any paint. Therefore, while this manual flooding process generally produces a secure and strong ice surface, it is also labour intensive, unsafe, and expensive.
As a result of the difficulties in using hot water floods, operators often use cold water floods instead. This is less expensive, since the cold water is less likely to melt through any ice already formed and the flooding need not be as carefully done. Cold water floods however produce ice that is less dense, has more voids and is thus softer. This means bigger chips and ruts are created by skates and results in more snow building up during skating. Excessive Snow is undesirable for hockey because it interferes with the free movement of the puck along the ice. Further, cold water floods result in ice which is typically cloudy, which obscures the painted lines and corporate logos. Lastly, the voids have an insulating effect. This is problematic because the cooling is provided at the bottom face of the ice surface whereas the skating activity takes place at the top of the ice surface. Drawing the heat away through a more insulating layer of ice is more energy expensive, and makes it more difficult to keep the surface cold and hard.
In addition to initial ice formation, typically ice surfaces upon which skating occurs have to be periodically resurfaced to eliminate the grooves and ruts made by skate blades. A standard technique is to use a resurfacing machine, one example of which is a resurfacer such as a “Zamboni”. Such resurfacing machines are typically self-propelled and include a scrapper blade to pick up snow and ice chips. The scrapper blade is followed by a rag or a cloth that is dragged over the ice surface. A flood pipe is connected to a reservoir of water. As the cloth is dragged over the ice surface, the water is spread by the cloth onto the ice surface. Thus, a film of water is distributed over the ice surface in the path of the cloth. As the water freezes, over a period of time, a new top coat of ice is formed.
Unfortunately, the water layer freezes rather slowly taking some time to turn into ice. The length of time that it takes the thin layer of water to freeze into an ice sheet means that often there are wet spots or the like on the ice surface for the portion of the ice most recently passed over by the resurfacer when the players wish to recommence playing hockey. Surface water also interferes with the free movement of the puck along the ice. Further it is believed that as the water slowly cools to form ice, gasses are absorbed into the water, which then creates more voids or freezing. Thus, there is a tendency for voids to form in the ice as it freezes which leads to a weak bond softer and cloudy ice surface even though hot water was used initially. The problem is worse if cold water is used.
In summary, the traditional methods used to form and to resurface ice sheets results in an unacceptable quality of ice which is both soft and cloudy by reason of the voids. The voids weaken and otherwise detract from the playability of the ice sheets. This problem is particularly acute for indoor rinks with large spectator crowds such as hockey and figure skating events. The large crowds tend to result in warm air temperatures which hasten the deterioration of already weak ice. What is needed is some way to create and resurface an ice surface which reduces the heat load on the ice the formation of voids and thus create a harder, longer wearing and more durable ice surface that is more energy efficient.